A-level · Data presentation

Measuring correlation (the PMCC)Exam-style questions

The product moment correlation coefficient r as a number between −1 and 1 measuring linear correlation — computing it from the summary statistics S_xy, S_xx, S_yy, interpreting it in context, and why coding leaves it unchanged.

Start practising Read the lesson

15 questions · A-level level · mark scheme and worked solution on each · no sign-up to try

DifficultyAll Level 2 Level 3

1
For a set of bivariate data, $S_{xy} = 100$ , $S_{xx} = 72$ and $S_{yy} = 152$ . Find the product moment correlation coefficient $r$ , to 3 decimal places.
Level 2 · 2 marksTry it
2
For a set of bivariate data, $S_{xy} = 60$ , $S_{xx} = 90$ and $S_{yy} = 160$ .

Calculate the product moment correlation coefficient. (2 marks)
Level 2 · 2 marksTry it
3
For each of the following, describe the correlation and suggest what it means in context.
(a) Hours of revision and exam mark: $r = 0.92$ . (2 marks)
(b) Shoe size and reaction time: $r = -0.15$ . (1 mark)
Level 2 · 3 marksTry it
4
For $8$ pairs of data: $\sum x = 48$ , $\sum y = 96$ , $\sum xy = 676$ , $\sum x^2 = 360$ , $\sum y^2 = 1304$ . Find $r$ to 3 d.p.
Level 3 · 4 marksTry it
5
For $10$ pairs of data: $\sum x = 50$ , $\sum y = 100$ , $\sum xy = 590$ , $\sum x^2 = 300$ , $\sum y^2 = 1200$ . Find $r$ to 3 d.p.
Level 3 · 4 marksTry it

10 more questions on measuring correlation (the pmcc)

Free with an account — just an email, no card. The whole bank, every mark scheme and worked solution.

Start free